The asymmetric and broad shape of the imaginary part of the electrical module is described by the exponent p of the exponential KWW
g] very close to the upper temperature in the cycle so it may be "rejuvenated" in each cycle, so that we see changes in KWW
parameters that are determined more by degradation than physical aging.
r] (t), were generally small, though the same would not necessarily apply to best-fit KWW
parameters, given their extreme sensitivity to only slight changes in the data.
It quantifies the degree of retardation time distribution; the KWW
function implies a spectrum of retardation times whose breadth is related to [[beta].
function, which is an empirically stretched exponential function, is mainly used to explain the time-dependent behavior of amorphous materials (16).
In the KWW
method, an estimate of the distribution of relaxation times can be obtained while in the Burger model a general parametric effect of long term and short term response is developed.
The experimental results were also fitted to the stretched exponential, the KWW
It is postulated that the KWW
equation is more appropriate in modeling relaxation processes than standard exponentials.
function introduced by Williams and Watts (31) was used by Wimberger-Friedl (29) to model the SOC.
function was applied to each experimental stress relaxation curve with no restrictions on the parameters.
The expression for modeling experimental KWW
material functions obtained from stress relaxation experiments is:
0] and to a model with 5 constants [48, 49] that employs the KWW
equation together with the Narayanaswamy relation for [[tau].